• Stomach Cells:
  • Parietal cell: Secretes Hydrochloric Acid (HCl) & Intrinsic Factor.
  • Chief cell: Secretes Pepsinogen.
  • Endocrine cells: D-cells secrete Somatostatin; G-cells secrete Gastrin and Histamine.
• Duodenum Cells:
  • Brunner's gland: Secretes alkaline mucus.
  • Endocrine cells: Secretin (decreases acid secretion) & Cholecystokinin (CCK) (causes Gallbladder contraction).

• Flexible Endoscope: The BEST tool for diagnosis, biopsy, taking samples for Helicobacter Pylori, and therapy (diathermy/laser).
• Contrast Study: Best for Paraesophageal hernia, Linitis plastica, Volvulus.
• Computed Tomography (CT) / Magnetic Resonance Imaging (MRI): Best for evaluating tumors and metastasis.

• Congenital Pyloric Hypertrophy:
  • Familial, more common in males, presents at 4 weeks of age.
  • Sign: Projectile vomiting after feeding, failure to thrive.
  • Diagnosis: Ultrasound (US).
  • Treatment: Resuscitation followed by Ramstedt operation (Pyloric myotomy).
• Duodenal Atresia:
  • Congenital diaphragm in the duodenal curve.
  • Sign: Same as pyloric hypertrophy but features Bilious vomiting.
  • Diagnosis: Double bubble appearance on X-Ray.
  • Treatment: Duodeno-duodenostomy.

• Characteristics: Gram-negative, helical shape. Located in the submucosal layer of the antrum.
• Mechanism: Secretes Urease enzyme (converts urea to ammonia) → stimulates gastrin → acid hypersecretion.
• Responsible for: Chronic gastritis, Peptic ulceration, Gastric cancer.
• Invasive Tests: Urease test, Histology (Giemsa stain for antral biopsy), Culture.
• Non-Invasive Tests: Urea breath test (labeled), Antibody isolation (IgG).

• Type A: Autoimmune against parietal cells → Intrinsic Factor deficiency → Pernicious anemia.
• Type B: Associated with H. Pylori in the antrum → intestinal metaplasia.
• Erosive Gastritis: Associated with Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Alcohol.
• Menetrier's Disease: Premalignant disease due to mucosal atrophy.

• Predisposing Factors: High acid (Zollinger-Ellison syndrome), NSAIDs, Steroids, H. Pylori, Blood group O, Smoking.
• Duodenal Ulcer (DU):
  • Most common type, more in males, younger age.
  • Involves 1st part of duodenum. May be "kissing".
  • Posterior ulcers usually bleed; Anterior ulcers usually perforate.
• Gastric Ulcer (GU):
  • Less common, older age group. Carries risk of malignancy.
  • Usually larger, causes stomach deformity (Hour-glass shape).
  • Perforates posteriorly into pancreas, splenic artery, or transverse colon.
• Medical Treatment: Proton Pump Inhibitors (PPIs) (e.g., Omeprazole) are the golden drugs for eradication.
• Eradication Therapy (Triple Therapy): Clarithromycin + Amoxicillin (or Metronidazole) + PPI for two weeks. Contraindicated in Zollinger-Ellison syndrome and NSAID-induced ulcers.
• Indications for Surgery: All complications, failure of medical Tx, serious deformity, suspicion of malignancy (Ulcer in greater curvature, positive cytology, long history, age > 60, pernicious anemia).
• Surgical Types:
  • DU: Billroth II, Gastrojejunostomy, Truncal Vagotomy (TV) + Pyloroplasty.
  • GU: Billroth I (preferred), Billroth II, Vagotomy + Pyloroplasty + Excision of ulcer.

• Perforation: Mainly caused by NSAIDs. Features: Sudden severe epigastric pain, chemical peritonitis followed by a lucid period, then bacterial peritonitis. Abdomen becomes rigid and does not move with respiration. Investigation: Chest X-ray shows 50% air under diaphragm. Serum amylase to exclude pancreatitis. Tx: Surgery to seal perforation + peritoneal toilet.
• Bleeding: Major emergency. Indications for emergency surgery: Spurting artery, Visible vessel at ulcer base, Clot at ulcer base. Indication after resuscitation: Re-bleeding, continuous bleeding.
• Gastric Outlet Obstruction: Features: Long history, weight loss, vomiting, succussion splash. Leads to Hyperchloremic alkalosis (paradoxical aciduria). Tx: Isotonic saline + Potassium supplement first, then surgery.

• Polyps: Inflammatory (fundus, associated with PPI), Metaplastic (H. pylori), Adenoma (malignant potential), Carcinoid (associated with pernicious anemia).
• Gastric Cancer:
  • Proximal: High socioeconomic class, NO H. Pylori.
  • Distal: Low socioeconomic class, associated with H. Pylori.
  • Features: Anemia, Asthenia, Anorexia. Metastatic features: Trousseau's sign (thrombophlebitis).
  • Spread: Lymphatic embolization (Troisier's Sign / Virchow's node), Transperitoneal (Rectal shelf tumor, Krukenberg tumor to ovaries), Umbilicus (Sister Mary Joseph nodule).

• H. Pylori Location: Specifically located in the submucosal layer of the antrum and works by secreting Urease.
• Vomiting Types: Projectile (non-bilious) = Congenital Pyloric Hypertrophy. Bilious = Duodenal Atresia.
• Duodenal Ulcer Rule of Thumb: Anterior ulcers perforate, while Posterior ulcers bleed.
• Golden Drug: Proton Pump Inhibitors (PPIs) are the golden drugs for H. Pylori eradication (given in Triple Therapy for 2 weeks).
• Virchow's Node: Also known as Troisier's Sign, signifies lymphatic embolization in Gastric Cancer.

• Clinical Features:
  • Absolute constipation is a LATE feature of small bowel obstruction. It is ABSENT in Richter hernia, gallstone ileus, and pelvic abscess.
  • Fever or Peritonism (rigidity/tenderness) strongly indicates Strangulation or perforation!
  • Bowel sounds: High-pitched and hyperactive initially, but absent in advanced cases.
  • Rectal Exam: In small bowel obstruction, the rectum is empty and ballooned out.
• Management:
  • Nasogastric (NG) suction for decompression and preventing aspiration.
  • IV Fluids (Isotonic saline or Ringer Lactate) - adequacy judged by urine output.
  • Conservative management (48 hours) is safe IF there are no features of peritonism/strangulation.

• Adhesions:
  • Fibrinous: Early post-operative, filmy, may disappear. Treat conservatively up to 48 hrs.
  • Fibrous: Late, vascularized, dense.
  • Bands: Congenital (obliterated vitello-intestinal duct) or Acquired. Needs laparotomy.
• Sigmoid Volvulus:
  • Twisting of bowel on its mesentery causing obstruction + ischemia.
  • X-Ray: Massive colonic distension, 'Bent inner tube' or 'Coffee bean' sign arising from the pelvis.
  • Tx: Conservative with rigid sigmoidoscopy and flatus tube (if no ischemia). Surgery (Hartmann's or primary anastomosis) if decompression fails.
• Caecal Volvulus:
  • Associated with incomplete midgut rotation (inadequate fixation). Usually twists clockwise.
  • X-Ray: Comma-shaped caecal shadow in mid-abdomen.
  • Tx: Laparotomy normally required (Right hemicolectomy if ischemic).
• Gallstone Ileus: Occurs in the elderly. Large stone erodes through gallbladder into duodenum. Impacts 60 cm proximal to the ileocaecal valve (narrowest part). X-Ray shows air in the biliary tree.
• Intussusception: Contrast (Hydrostatic) enema is diagnostic in 95% of cases and is also therapeutic/curative if duration is less than 24 hours.

• Absolute Constipation: Remember it is a LATE feature in small bowel obstruction, not an early one.
• Fever & Peritonism: If present in a bowel obstruction case, immediately suspect Strangulation or Perforation.
• Adhesions Rule: They are the main cause of post-operative obstruction; Fibrinous = early/conservative, Fibrous = late/surgery.
• Radiology Signs: "Bent inner tube" / "Coffee bean" = Sigmoid Volvulus. "Comma-shaped" = Caecal Volvulus.
• Gallstone Ileus Site: The stone almost always impacts 60 cm proximal to the ileocaecal valve (the narrowest point).

• Pathogen: Echinococcus granulosus (produces unilocular cystic lesions). Zoonotic Cestode.
• Ultrasound (US) Features:
  • CL: Unilocular anechoic cyst, no internal echoes.
  • CE1: Uniformly anechoic cyst with fine echoes representing Hydatid Sand.
  • CE2: Multiple septations giving Rosette, Multivesicular, or Honeycomb appearance. This is the Active Stage.
  • CE3: Detached laminated membranes appearing as Water Lily Sign. This is the Transitional Stage.
  • CE4: Mixed contents giving a Ball of Wool Sign (degenerative nature).
  • CE5: Arch-like, thick, calcified wall. This is Inactive and Infertile.
• Computed Tomography (CT) Scan: Has the highest sensitivity (98%). Best for number, size, location, and detecting complications (rupture/infection).
• Magnetic Resonance Imaging (MRI): Superior to CT in demonstrating alteration of the hepatic venous system. MRCP is useful for biliary communications.

• Medical Treatment (Albendazole): Dose: 10-15 mg/kg/day (or 400 mg twice daily). Given in 28-day cycles with a 2-week break. Contraindicated in pregnancy (causes bone marrow suppression & elevated liver enzymes).
• PAIR (Puncture, Aspiration, Injection, Reaspiration):
  • Indications: Surgically unfit, relapse cysts, pregnant women, children < 3 years, stages CL, CE1, CE2, CE3.
  • Contraindications: Inaccessible/superficial cysts, honeycomb cysts, communicating cysts to bile duct, calcified cysts, lung cysts.
  • Procedure: Use 95% alcohol or hypertonic saline (15-20%) as scolicidal agent. Wait 20 minutes before reaspiration. Must have anaphylaxis drugs (epinephrine) ready.
• Surgery:
  • Pre-op Albendazole for 1 week and post-op for 4 weeks minimizes recurrence by >50%.
  • Goal: Inactivate cyst contents, prevent spillage, manage residual cavity.
  • Steps: Isolate field with colored mops soaked in scolicidal agent. Aspirate fluid to reduce pressure before opening.
  • Complications: Biliary leakage is the most frequent postoperative complication (50%). Recurrence up to 11.3%.

• Best Imaging: CT scan is the absolute best for sensitivity (98%), size, number, and complications.
• Albendazole Warning: It is strictly Contraindicated in pregnancy.
• PAIR Fatal Risk: Always have Epinephrine ready during PAIR or surgery due to the risk of Anaphylaxis from cyst spillage.
• Post-Op Complication: Biliary Leakage is the most frequent complication (50%) after surgical excision.
• US Hallmarks: CE2 = Active (Honeycomb). CE3 = Transitional (Water Lily). CE5 = Inactive (Calcified).

• Rectum: Length = 12 cm. Begins at rectosigmoid junction (sacral promontory), ends 2.5 cm below/in front of coccyx tip.
• Anal Canal: Length = 4 cm. Extent: anorectal junction to anus. Features the Dentate (pectinate) line.
• Bleeding Types:
  • Bright red = Anal or Rectum source.
  • Dark = Proximal lesion (higher colon).
• Pain: Painless = Hemorrhoids and Rectal Carcinoma. Painful = Anal Fissure, Abscess.
• Investigations: Proctoscope (inspects 10-12 cm, can take biopsy). Flexible Sigmoidoscope (60 cm, reaches splenic flexure, detects 50% of colorectal cancers).

• Definition: Symptomatic anal cushions. Common with raised intra-abdominal pressure (obesity, pregnancy, constipation).
• Classic Sites: Left lateral (3 o'clock), Right posteriolateral (7 o'clock), Right anterolateral (11 o'clock) (Lithotomy position).
• Degrees:
  • 1st degree: Bleed only, no prolapse.
  • 2nd degree: Prolapse but reduce spontaneously.
  • 3rd degree: Prolapse, must be manually reduced (Indication for Hemorrhoidectomy).
  • 4th degree: Permanently prolapsed.
• Complications: Strangulation, Thrombosis, Portal pyaemia, Fibrosis. Early post-op complication of hemorrhoidectomy is Acute Urinary Retention.

• Fissure-in-ano: Longitudinal split in anal canal skin. Common sites: Midline 6 and 12 o'clock. Operative Tx: Lateral internal sphincterotomy.
• Anorectal Abscess: Bacterial infection of blocked anal gland at dentate line (E. coli, Staph aureus). Sites: Perianal, Ischiorectal, Pelvirectal, Intersphincteric. Tx: Incision and drainage + Antibiotics.
• Fistula-in-ano: Abnormal communication between two epithelium-lined surfaces. Mostly due to cryptoglandular sepsis (50% secondary to Crohn's, Tuberculosis, Rectal CA).
• Parks Classification (Fistula):
  1. Intersphincteric (45%)
  2. Transsphincteric (30%)
  3. Suprasphincteric (20%)
  4. Extrasphincteric (5%)

• Rectal Prolapse: Eversion of WHOLE thickness of lower rectum and anal canal. Differentiated from intussusception by anatomy (no gap between bowel and anus). Complete prolapse treated with Thiersch wire.
• Pilonidal Sinus: Sinus containing a tuft of hairs, mainly over sacrum/coccyx, but also in umbilicus or between fingers of hairdressers.
• Anal Neoplasm: Epidermoid carcinoma is the most common. Highly prone to Human Papillomavirus (HPV) infection.

• Pain vs. Bleeding: Remember, Hemorrhoids and Rectal Cancer are strictly Painless. Anal Fissure and Abscess are Painful.
• Hemorrhoid Sites: 3, 7, and 11 o'clock positions (in lithotomy) are the classic anatomical sites.
• Anal Fissure Sites: Almost always found at midline 6 o'clock or 12 o'clock positions.
• Fistula Origins: Most common cause is Cryptoglandular sepsis; however, 50% can be secondary to Crohn’s or TB.
• Post-Hemorrhoidectomy Retention: Acute Urinary Retention is a classic early complication of hemorrhoidectomy surgery.

• Anatomy: 75-150 gm. Lies between 10th-11th ribs posteriorly. Hilum contains splenic vessels and tail of pancreas. Contains Red and White pulp.
• Functions: Immune function (Ig formation, white pulp), filtration of abnormal RBCs, iron reutilization, blood volume reservoir, haemopoiesis, and sequestration of platelets.
• Congenital Anomalies: Spleniculi (accessory spleens found in hilum, greater omentum, tail of pancreas). Hamartoma (normal epithelium abnormally arranged).

• Blunt Trauma: Treated conservatively or surgically based on severity.
• Penetrating Trauma: Demands Laparotomy.
• Clinical Types:
  1. Rapid death from massive bleeding.
  2. Initial shock → recovery → signs of bleeding. Signs include: Upper abdominal pain, Kehr's sign (Left shoulder pain), shifting dullness.
  3. Delayed rupture due to dislodgment of hematoma.
• Radiological Features: Obliteration of splenic outline, Obliteration of psoas shadow, indentation of gastric outline, fractured ribs, elevated left hemidiaphragm.

• Indications: Trauma, En-bloc with gastrectomy, Hypersplenism (to reduce anemia in Immune Thrombocytopenic Purpura (ITP) or spherocytosis), Portal hypertension shunt surgery, staging of lymphoma.
• Complications: Hemorrhage, Gastric dilatation, left side atelectasis, Trauma to pancreas tail (fistula/abscess), Thrombocytosis and leukocytosis.
• OPSI (Opportunistic Post Splenectomy Infection): Lethal septicemia (Streptococcus pneumoniae, Neisseria). Risk increased in radiotherapy/chemotherapy and operations for hemolytic diseases.
• Prevention: Pneumovax 2 weeks pre-operatively + Penicillin prophylaxis post-op until 18 years of age. Conservative surgery (partial splenectomy, auto-transplant) preferred in patients < 40 years old.

• Kehr's Sign: Left shoulder pain indicating diaphragmatic irritation, a classic sign of ruptured spleen.
• OPSI Microorganisms: Streptococcus pneumoniae and Neisseria are the most lethal threats post-splenectomy.
• Pancreatic Tail Risk: Because the tail of the pancreas lies in the splenic hilum, it is highly prone to trauma/fistula during splenectomy.
• Pre-Op Vaccine: Pneumovax MUST be given exactly 2 weeks pre-operatively to prevent OPSI.
• Delayed Rupture: Sudden shock days after trauma is due to the dislodgment of an established hematoma.

• Anatomy: Retroperitoneal, ~80g. The neck is the landmark for the union of the splenic vein and superior mesenteric vein forming the Portal Vein.
• Congenital Anomalies:
  • Annular Pancreas: Bilious vomiting in early life, associated with Down's syndrome, shows Double Bubble sign on X-ray.
  • Congenital Pancreatic Cyst: Associated with Cystic Fibrosis (Diabetes Mellitus, steatorrhea).
  • Ectopic Pancreas: Found in stomach, duodenum, small bowel.
• Physiology:
  • Exocrine (80-90%): Stimulated by Vagus, Secretin, Cholecystokinin (CCK). Produces Bicarbonate & Trypsin.
  • Endocrine (10%): Alpha cells = Glucagon; Beta cells = Insulin; D cells = Somatostatin.

• Causes: 90% Biliary Colic (Gallstones obstructing Ampulla of Vater), 10% Alcohol. Others: ERCP, Trauma.
• Mechanism: Activation of intracellular enzymes (Trypsin) causing autodigestion.
• Clinical Features: Severe epigastric pain radiating to the back, patient leaning forward to relieve pain.
• Specific Signs:
  • Cullen's Sign: Periumbilical ecchymosis.
  • Grey Turner's Sign: Flank ecchymosis.
• Investigations: Serum Amylase increases 4 times normal (but normal level does NOT exclude it). X-ray shows Cut-off sign of colonic shadow.
• Severity Assessment (Ranson's Criteria): On admission (Age, WBC, Glucose, LDH, AST). After 48 hours (BUN, PCV, Serum Calcium, fluid sequestration, base deficit).
• Management: Mild (Nil By Mouth - NBM, IV fluids, Antibiotics). ERCP if CBD stone is present. Surgical excision ONLY for Radiologically diagnosed necrosis.

• Chronic Pancreatitis: Irreversible progressive damage. Tx: Fat-free diet, enzyme supplementation, stop alcohol/smoking. Surgery indicated for mass, chronic pain, or ductal/venous thrombosis.
• Pancreatic Carcinoma:
  • 80% are Ductal Cell Carcinoma. Predisposing factors: Alcohol, Chronic Pancreatitis.
  • Features: Weight loss, Painless Jaundice.
  • Courvoisier's Law: In the presence of a palpably enlarged gallbladder with painless jaundice, the cause is unlikely to be gallstones (points to Pancreatic Cancer).
  • Treatment: 95% are unresectable at diagnosis (due to Superior Mesenteric Artery/Node spread). Palliative stenting for jaundice. Surgery: Head tumor → Choledochojejunostomy. Tail tumor → Resection.

• Courvoisier's Law: Painless jaundice + palpable gallbladder = Pancreatic Cancer (NOT gallstones).
• Pancreatitis Cause: 90% of acute pancreatitis cases are caused by Gallstones (Biliary Colic).
• Specific Skin Signs: Cullen's sign (periumbilical) and Grey Turner's sign (flank) indicate severe retroperitoneal bleeding in acute pancreatitis.
• Amylase Trap: Serum amylase increases 4x in pancreatitis, but a normal level does NOT exclude the diagnosis.
• Anatomical Landmark: The neck of the pancreas is the exact site where the splenic vein and superior mesenteric vein join to form the Portal Vein.

• Definition: Artificial opening in the large bowel to divert feces and flatus to the exterior into an appliance. (Colostomy = Solid contents; Ileostomy = Fluid contents).
• Types: Temporary or Permanent.
• Temporary Loop Colostomy: Most common type. Sited in mobile bowel parts to divert content proximal to a pathology or trauma. Prevents peritonitis. Opened after abdominal closure, closed after distal pathology is cured (must confirm distal patency radiologically first).

• Appliances: Feces collected in disposable adhesive bags. Stoma care service is fundamental for psychological and practical support.
• Complications:
  • Prolapse and Retraction.
  • Necrosis of the distal end (vascular compromise).
  • Parastomal (Colostomy) Hernia.
  • Skin Irritation.
  • Stenosis of the orifice.
  • Fluid and electrolyte disturbances (more severe in ileostomies).

• Output Difference: Colostomy output is generally solid; Ileostomy output is highly fluid (higher risk of electrolyte disturbance).
• Most Common Type: The Temporary Loop Colostomy is the most widely performed.
• Rule of Closure: A temporary stoma MUST NEVER be closed until distal patency is confirmed radiologically.
• Early Complications: Prolapse, Retraction, and Necrosis are common mechanical complications of the stoma.
• Management Tool: Essential to use proper disposable adhesive bags with comprehensive stoma care service.

Feature	Duodenal Ulcer (DU)	Gastric Ulcer (GU)
Incidence / Age	Most common, younger age group	Less common, older age group
Gender	More common in males	More common in males (but older)
Location	1st part of duodenum	Lesser curvature of stomach
Malignancy Risk	No risk	Carries risk of malignancy
Complications Rule	Anterior perforates, Posterior bleeds	Perforates posteriorly to pancreas/splenic artery
Deformity	Fibrosis/kissing morphology	Hour-glass shape deformity
Surgical Preference	Billroth II, Vagotomy + Pyloroplasty	Billroth I (preferred)

Feature	Pyloric Hypertrophy	Duodenal Atresia
Pathology	Hypertrophy of the pyloric muscle	Congenital diaphragm in duodenal curve
Vomiting Type	Non-bilious (Projectile)	Bilious (Projectile)
Age of Onset	Usually at 4 weeks	Early neonatal period
Diagnosis (X-Ray/US)	Ultrasound (US)	"Double bubble" appearance on X-Ray
Surgical Treatment	Ramstedt operation (Pyloric myotomy)	Duodeno-duodenostomy

Feature	Sigmoid Volvulus	Caecal Volvulus
Etiology / Predisposition	Elderly, constipation, long mesentery	Incomplete midgut rotation (congenital)
Twisting Direction	Anticlockwise	Clockwise
Radiological Sign	'Bent inner tube' or 'Coffee bean' sign	'Comma-shaped' caecal shadow
Initial Treatment	Conservative: rigid sigmoidoscopy + flatus tube	Laparotomy is usually required

Feature	Bright Red Blood	Dark Blood
Source Location	Distal (Anal canal or Rectum)	Proximal (Higher colon / large bowel)
Common Causes	Hemorrhoids, Anal Fissure	Colorectal CA, Diverticulitis, IBD

Feature	Painful Conditions	Painless Conditions
Primary Pathology	Anal Fissure, Anorectal Abscess	Internal Hemorrhoids, Rectal Carcinoma
Clinical Clue	Patient fears defecation due to severe pain	Noticed only by bleeding or mass (Prolapse)

Feature	Fibrinous Adhesions	Fibrous Adhesions
Onset	Early post-operative	Late post-operative
Nature	Filmy, avascular, may disappear	Dense, vascularized, mature tissue
Treatment Approach	Conservative (NG tube, IV fluids up to 48h)	Often requires surgical intervention

PAIR Indications	PAIR Contraindications
Surgically unfit patients / Refusal of surgery	Inaccessible or superficially located cysts
Cyst stages: CL, CE1, CE2, CE3	Honeycomb cysts (Multiple septae)
Relapse cysts after previous surgery	Communicating cysts to bile duct
Pregnant women & Children < 3 years	Calcified cysts (CE5) & Lung cysts

Degree	Clinical Presentation	Reduction Method
1st Degree	Bleeds only, NO prolapse	N/A (No prolapse)
2nd Degree	Prolapses during defecation	Reduces spontaneously
3rd Degree	Prolapses easily	Must be manually reduced
4th Degree	Permanently prolapsed	Cannot be reduced

Feature	Cullen's Sign	Grey Turner's Sign
Location of Ecchymosis	Periumbilical (around the umbilicus)	Flank areas (sides of the abdomen)
Significance	Indicates retroperitoneal bleeding / severe acute pancreatitis	Indicates retroperitoneal bleeding / severe acute pancreatitis